JPH01295253A - Image forming method - Google Patents

Abstract

PURPOSE:To obtain the high color density of a recording material, maintaining a good shelf-life even in case of applying the thermal development to the recording material at a low temp. by forming a recording image by uniformly heating the recording material in the presence of a very small amount of water, and the recording material is formed by applying a dispersion composed of fine particles contg. a labelling org. material capable of chemically or physically distinguishing a photosensitive org. material, etc., on a supporting body. CONSTITUTION:The recording material is formed by applying the dispersion composed of fine particles contg. the labelling org. material capable of chemically or physically distinguishing the photosensitive org. material such as a diazonium compd., and an aromatic diazonium salt, etc., the photodissociation product of the photosensitive org. material and the substance thereof, on the supporting body, and the obtd. recording material is uniformly heated in the presence of the very small amount of water by a heating means to form the recording image. A means or a device capable of uniformly applying the very small amount of water on the recording material is provided immediately before the heating means or at the same position to that of said means or device. Thus, the high color density of the recording material is obtd., maintaining the god shelf-life even in case of applying the thermal development to the recording material at the low temp.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to photosensitive recording materials, and particularly to recording materials that have a good shelf life and can provide high color density even by low-temperature thermal development, and images thereof. Regarding the forming method.

<Prior Art> The present invention provides an image forming method in which the recording material is exposed to light corresponding to the image of the original to form a latent image on the recording layer, and then the entire recording layer is heated by a heating means to develop the image. Regarding the forming method. The latent image formed on the recording layer by exposure to light can be a corresponding latent image or a negative image depending on whether the photosensitive organic material or organic labeling material used in the recording layer is activated or inactivated by light irradiation. It may be a statue of Riposi.

Conventionally, labeling organic substances that chemically or physically distinguish between photosensitive organic substances and photodecomposition products of the photosensitive organic substances are those that cause a reaction, phase change, or material permeability change by applying thermal energy to the system. It was known as a group of compounds that cause Therefore, when assembling a recording system using the above changes, the less thermal energy required, the cheaper and more compact the system becomes possible.

However, it is essential that the performance of the recording materials applied to the above-mentioned recording system does not change as much as possible depending on the storage conditions and storage period before recording, and this means that the thermal energy required for recording can be reduced. This contradicted the other requirement, which was to reduce the amount of waste as much as possible. In other words, the more a recording material can be developed at a lower temperature, the more likely a mutual change will occur between the photosensitive organic substance and the labeling organic substance during storage before recording, causing a recorded image to appear in an area that should originally be an unrecorded area. This causes the inconvenience of formation. (Generally, it is often referred to as fog.) Therefore, an object of the present invention is to provide a recording material that has a good shelf life and can obtain high color density even by low-temperature thermal development, and an image forming method thereof. .

An object of the present invention is to provide a photosensitive organic substance, a photodecomposition product of the photosensitive organic substance, and a label capable of chemically or physically distinguishing these substances on a support. This was achieved by an image forming method in which a recorded image is obtained by uniformly heating a recording material coated with a fine particle dispersion containing an organic substance by a heating means in the presence of a trace amount of water. In the present invention, a trace amount of moisture may be supplied from outside the recording material, or a trace amount of moisture may be prepared in advance inside the recording material.
It also meets the purpose of the present invention that it is supplied from within by means of external splinters. In the present invention, when a trace amount of water is supplied from outside the recording material, a process and equipment for uniformly applying a trace amount of water immediately before or at the same position as the heating means is provided, or immediately before or at the same position as the heating means. It is preferable to provide a step of heating with steam and a slit for uniformly blowing out the steam at the same position. Also,
In the present invention, a small amount of moisture is prepared in advance inside the recording material, and if it is supplied from the inside by an external stimulus, it is placed in front of or at the same position as the heating means depending on the external stimulus to be used. It also meets the purpose of the present invention to provide a process and equipment for uniformly pressurizing the recording material, or to heat it with a heating means without providing any special process or equipment.

In the present invention, a fine particle dispersion containing a photosensitive organic substance, a photodecomposition product of the photosensitive organic substance, and a labeling organic substance capable of chemically or physically distinguishing these substances is coated on a support. The basic process is to obtain a recorded image by heating the recorded recording material with a heating means, or to achieve high-speed recording, each component instantaneously melts, diffuses, and reacts due to heating and becomes visible as a recorded image. must be transformed into In order to reduce the thermal energy as much as possible in this heating process, in addition to transmitting heat to the recording material without wasting it and using the heat transferred to the recording material to form a recorded image without wasting it, the recording image forming system itself must be kept at a low temperature. There are three ways to make it possible. 1st,
For method 2, for example, the surface of the recording material should be smoothed to ensure complete contact with the heating means, or the support should be heat-insulated to prevent heat loss from the support side. A method is presented. However, all of these methods were insufficient for the purpose of the present invention.

Therefore, the inventors of the present invention conducted intensive studies to make the recorded image forming system itself practical at low temperatures, and as a result, they arrived at the present invention.

In other words, it was necessary to discover a means of melting substances at low temperatures, as long as it was based on the fact that substances change when heated. It is well known that the melting point of a mixture is lower than the melting point of each pure substance. Therefore, the present inventors have determined the melting point of organic substances involved in the formation of recorded images.
After testing countless compounds to see if they could be reduced by adding new substances, we found that, surprisingly, simple water was the most effective, and polyurea and polyurethane were among the organic substances involved in forming the recorded image. We have discovered that the presence of this substance is even more effective.

Therefore, the photosensitive organic substance is encapsulated in microcapsules in advance, and the capsule wall of the microcapsules is made of at least one material selected from polyurea or polyurethane.
Preference is given for the purposes of the invention to the recording materials described, which are characterized in that they are formed by polymers of various types.

In the present invention, the photosensitive organic substances include the following compound groups, but the present invention is not limited thereto.

“Photodecomposition and chemical structure of photosensitive diazonium salts” (Takahiro Tsunoda, Ao Yamaoka, Journal of the Photographic Society of Japan 29 (4) 197-2
05 (1965)), aromatic diazonium salts, diazosulfonate compounds,
Diazoamino compounds.

Photo, Sci, En9.5.98 (1961
), photooxidizing agents described in Japanese Patent Publication No. 43-29,407, etc. Typical photo-oxidizing agents include carbon tetrabromide, N
-bromosuccinimide, tribromomethylphenylsulfone, azide polymer, niazidobenzoxazole, benzoyl azide, 2-azidobenzimidanol,
3-Ethyl-1-methoxy-2-pyridothiacyanine verchlorate, 1-methoxy-2-methylpyridinium-p-toluenesulfonate, 2,4.5-triarylimidazole dimer, benzophenone, p-7 minof These include enyl ketones, polynuclear quinones, and thioxanthenones. A photocrosslinking agent whose principle is applied to photocrosslinkable photosensitive resins. Examples include vinyl cinnamate, coumarin, anthracene, and 2-methyl-5-vinylpyridine. A compound known as an organic photochromic material. Examples include spiropyrans, triphenylmethane dyes, anils, azohenzenes, tetrachlorodihydronaphthalenes, and benzylpyridines.

In the present invention, the organic substances for labeling include the following compound groups, but the present invention is not limited thereto.

For diazo compounds, coupling components with phenols, naphthols, active methylene compounds, etc. For example, resorcin, phloroglucin, 2-hydroxy-3-
Naphthoic acid anilide and 113-bis-(pivaloylacetaminomethyl)benzene are among the oldest.

For photo-oxidizing agents, these include, for example, leuco dyes, which have one or two hydrogen atoms and whose removal and, in some cases, addition of additional electrons, form a coloring layer to form a dye. . 7-minotriarylmethane, aminoxanthine, amino-1, described in U.S. Pat. No. 3,445.234;
Examples include 9-dihydroacridine, aminophenoxazine, aminodihydrophenazine, leucoindamine, hydrazine, and phenethylaniwan.

In the present invention, trace amounts of water may be conveniently supplied by any of the methods described above, or from 0.19/m2 to 20
It is preferable to adjust it so that it becomes q/m2.

In the present invention, when a small amount of water is supplied to the recording material by coating, the method is not only the usual spray coating, dip coating, coating with a coating bar, etc.
For example, "Coating Engineering" by Yuji Harasaki, page 253 (1
You can choose from the methods described in the book (published by Asakura Shoten in 1987).

When a trace amount of water is supplied to the recording material by coating in the present invention, an aqueous solution of a known 7-ionic or nonionic surfactant can be used. Preferred surfactants include sodium alkylhenzenesulfonate,
Examples include sodium alkyl sulfate, dioctyl sodium sulfosuccinate, polyalkylene glycol (eg, polyoxyethylene nonylphenyl ether), and the like. Further, pigment dispersants, thickeners, flow modifiers, antifoaming agents, foam inhibitors, mold release agents, coloring agents, and the like may be appropriately blended into the aqueous solution as required.

The microcapsules encapsulating a photosensitive organic substance of the present invention are
For example, it can be prepared by the method described in JP-A-59-190886. The polyurea and polyurethane that form the walls of the microcapsules can be obtained by polymerizing the corresponding monomers by the method described above.
, the wall thickness is determined to be between 0.01 and 0.3.

In the present invention, it is also possible to use Ijl water by pre-encapsulating it in microcapsules.
10, 3,856,699° and 3,427,250.

Further, examples of compounds containing crystal water or structured water in the molecule used in the present invention include, for example, the above-mentioned U.S. Pat.
It is described in 10 specifications.

As the support C of the present invention, any paper support used for ordinary pressure-sensitive paper, thermal paper, dry or wet diazo copying paper, etc. can be used, as well as neutral size supports such as alkyl ketene dimer. Neutral paper with a pH of 6 to 9 (described in Japanese Patent Application No. 55-14281), which has been sized with a pH 6 to 9 neutral paper (described in Japanese Patent Application No. 55-14281), which satisfies the relationship between Steckigt sizing degree and metric basis weight described in Japanese Patent Application Laid-Open No. 57-116687, and Paper with a smoothness of 90 seconds or more, paper with an optical surface roughness of 8μ or less and a thickness of 30 to 150μ as described in JP-A-58-136492, a density of 0.99 as described in JP-A-58-69091 /cm
Paper with an optical contact ratio of 3 or less and an optical contact ratio of 15% or more, JP-A-5
Canadian Standard Freeness (JIS) as described in No. 8-69097
P8121) Paper made from pulp beaten to 400cc or more to prevent coating liquid from seeping in, JP-A-58
-65695, the glossy side of base paper made by a Yankee machine is used as the coating surface to improve the color density and resolution, and the base paper described in JP-A-59-35985 is subjected to corona discharge treatment to improve coating suitability. You can also use improved paper.

Furthermore, the synthetic resin film used as a support in the present invention can be arbitrarily selected from known materials that do not deform even when heated during the development process and have dimensional stability. Examples of such films include polyester films such as polyethylene terephthalate and polybutylene terephthalate, cellulose derivative films such as cellulose triacetate films, polystyrene films, polypropylene films, and polyolefin films such as polyethylene. Can be used. The thickness of the support is 20 to 200
μ is used.

The heating means used in the present invention includes, for example, a thermal pen, a thermal head, an infrared ray, a high frequency, a heat block,
Examples include heat rollers.

<Effects of the Invention> As detailed above, the present invention has realized an image forming method that has a good shelf life and provides high color density even by low-temperature thermal development.

The development temperature can be set arbitrarily depending on the characteristics of the material such as the photosensitive organic material used and the development conditions, or the present invention has made it possible to freely select a development temperature of 1508 C or lower, which was previously impossible.

The heat development temperature of the present invention is determined by several factors, such as ensuring that the record is completely dry after development, that curling is not large, and that the recording speed is fast.
It is possible to set it in the range of 60°C to 140°C.

Hereinafter, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited by these Examples.

<Example> 3.45 parts of 1-morpholino-2,5-dibutoxybenzene-4-diazonium hexafluorophosphate, xylylene diinocyanate and trimethylolpropane (3.45 parts)
:1) 18 parts of the adduct were added to a mixed solvent of 6 parts of tricresyl phosphate and 5 parts of ethyl acetate, and dissolved by heating. This diazo compound solution was mixed with an aqueous solution containing 5.2 parts of polyvinyl alcohol dissolved in 58 parts of water, and emulsified and dispersed at 20°C to obtain an emulsion having an average particle size of 2.5 μm. 100 parts of water was added to the obtained emulsion and heated to 60°C while stirring, and after 2 hours, a capsule liquid containing the diazo compound in the core substance was obtained.

Next, 10 parts of 2-hydroxy-3-naphthoic acid anilide and 10 parts of triphenylguanidine were added to 200 parts of a 5% polyvinyl alcohol aqueous solution and dispersed in a Santomil for about 24 hours to obtain a dispersion with an average particle size of 3 μm.

To 50 parts of the capsule solution of the diazo compound obtained as described above, 50 parts of a dispersion of a coupling component and triphenylguanidine and 10 parts of a 40% calcium carbonate dispersion were added to prepare a coating liquid. Spread this coating solution on smooth high-quality paper (7
59/m2) using a coating bar to dry weight 10
Copying material A was prepared by applying the coating material in an amount of q/m2 and drying at 50°C for 1 minute.

A test manuscript (a circle with a diameter of 3 cm on tracing paper painted uniformly black with a 2B pencil) was placed on copy material A and exposed to light using a fluorescent lamp.

At this time, a fluorescent lamp having an emission spectrum of 420 nm was used. Next, an image was formed by heating for 3 seconds using a heat block heated to 120°C. Similarly, set the temperature of the heat block to 80°C, 1
It was also tested at 00°C.

On the other hand, after exposure and before heating, copying material A was coated with 2 q/m2 of water using a coating bar, and then similarly heated using a heat block. In addition, in order to test the shelf life, the samples were stored at 40°090% R1-1 for 24 hours, exposed in the same manner, and developed at various temperatures. 60'C30%R
A 24-hour storage test was also conducted with H. The densities of the colored parts and background parts of the samples obtained in each test were measured using a Macbeth densitometer. Table 1 shows the results of tests at different heating temperatures, and Table 2 shows the results of the pre-copy storage test.

As shown in Table 1, it can be seen that sufficient color density can be obtained even at low temperatures when developing in the presence of dampening water. When combined with the results shown in Table 2, the effects of the present invention become clear.

In the table, (*) indicates that the test was conducted with dampening water, and (-) indicates that the test was conducted without dampening water.

Claims (1)

[Scope of Claims] 1) A fine particle dispersion containing a photosensitive organic substance, a photodecomposition product of the photosensitive organic substance, and a labeling organic substance capable of chemically or physically distinguishing these substances is disposed on a support. An image forming method in which a recorded image is obtained by uniformly heating a recording material coated in the presence of a trace amount of water. 2) The image forming method according to claim 1, further comprising a step and equipment for uniformly applying a small amount of moisture immediately before or at the same position as the heating means. 3) The image forming method according to claim 1, further comprising a step of heating with water vapor and a slit for uniformly blowing out the water vapor immediately before or at the same position as the heating means. 4) The image forming method according to claim 1, further comprising a step and equipment for uniformly pressurizing the recording material immediately before or at the same position as the heating means. 5) The photosensitive organic substance is pre-encapsulated in microcapsules, and the capsule wall of the microcapsules is formed of at least one kind of polymer selected from polyurea or polyurethane. Recording material described in Section 1. 6) The photosensitive organic substance is pre-encapsulated in microcapsules, and the capsule wall of the microcapsules is formed of at least one kind of polymer selected from polyurea or polyurethane. Recording material described in Section 2. 7) The photosensitive organic substance is pre-encapsulated in microcapsules, and the capsule wall of the microcapsules is formed of at least one kind of polymer selected from polyurea or polyurethane. Recording material described in Section 3. 8) The recording material according to claim 1, wherein a trace amount of water is previously encapsulated in microcapsules and applied. 9) The recording material according to claim 4, wherein a trace amount of water is previously encapsulated in microcapsules and applied. 10) The recording material according to claim 1, which is coated with a compound in which a trace amount of water is present in molecules as crystal water or structured water.